Deadline orientated people get things done by the specified date (for the most part). However, they can also stress themselves out meeting that goal, which can spread into their non-writing life and create all sorts of issues. As well, the quality of their writing can take a big hit if all they worry about is meeting their deadline.
On the flip side of this, the "go with the flow" types write when they feel inspired. Their work isn't likely to take a hit from being stressed, because they only work when they feel the need to. However, this can mean they take years to finish one project and by that time the voice at the beginning of the story might not mesh with the voice at the end of the story (among other issues). As well, if they are published, they need to be able to work under deadlines with their publisher.
Do you make deadlines or are you a "go with the flow" type? What pros and cons can you think of for each?